Colombia's government on Saturday blamed the nation's largest remaining rebel group for an explosion outside a police base that injured 11 officers and killed a police dog.
The attack took place early Saturday in Cucuta, a city along Colombia's border with Venezuela, where drug gangs and rebel groups have long fought for the control of smuggling routes.
General William Rincon, the director of Colombia's police, said the blast came from a truck that had been left outside a building that serves as the headquarters for police in Norte de Santander Province. The pre-dawn explosion damaged much of the building's roofing and shattered its windows.
The attack comes as Colombia prepares to inaugurate a new president.
Next Friday, Abelardo de la Espriella, an ultra conservative who has promised to cancel peace talks with the nation's remaining rebel groups, will be sworn into office in Cali, another Colombian city where rebel groups have staged attacks recently.
The National Liberation Army, or ELN, has been fighting Colombia's government for decades, and is believed to have 6,000 fighters operating in Colombia and neighbouring Venezuela.